In Yin et al. (Nature Cell Biology 4, 462–467, (2002)), the authorship should be Yin, Y., Stephen, C. W., Luciani, M. G. & Fahraeus, R., with C. W. Stephen and Y. Yin having made equal contribution to this work. There was also an error in the labelling of Fig. 3. In Fig. 3b, the graph should have been labelled M/AA rather than A/MM. In Fig. 3d, μm should read µg. This has now been corrected online.